The cheesesteak was developed in the early 20th century "by combining frizzled beef, onions, and cheese in a small loaf of bread," according to a 1987 exhibition catalog published by the Library Company of Philadelphia and the Historical Society of Pennsylvania.
Philadelphians Pat and Harry Olivieri are often credited with inventing the sandwich by serving chopped steak on hoagie rolls in the early 1930s. They began selling this variation of steak sandwiches at their hot dog stand near south Philadelphia's Italian Market. They became so popular that Pat opened up his own restaurant which still operates today as Pat's King of Steaks. The sandwich was originally prepared without cheese. Olivieri claims provolone cheese was first added by Joe "Cocky Joe" Lorenza, a manager at the Ridge Avenue location."
Pat's and Geno's Steaks have a highly publicized rivalry. They are located across the street from each other on 9th Street and Passyunk Avenue in South Philadelphia. Cheesesteaks have become popular in restaurants, cafeterias and food carts throughout the city with many locations being independently owned family run businesses.Variations of cheesesteaks are now common in several fast food chains. Versions of the sandwich can also be found in locations ranging from bars to high-end restaurants.